1. Field of Invention
This invention pertains to an apparatus and method for playing electronic media using metadata attached to the media as a control parameter in a manner that prevents unauthorized play of the media.
2. Description of the Prior Art
A. Unauthorized Copying of Media
The advent of digitized media has brought with it the facility for lossless copying of digitized music, television, and movies, and has given even a novice the ability to easily and rapidly transport unauthorized pirated material from one computer or media device to another. Content pirates can acquire content from digital sources like Digital Video Disc (DVD) and Compact Disc (CD), or can simply digitize and compress media from analog sources (e.g. VCRs, cable television, Cassette Tape, LP, etc.) using nothing more than an inexpensive home computer.
Pirating is a tremendous threat to content providers, who spend large amounts of money producing music, films, and other types of programming, and expect to generate revenue from the sale, licensing and presentation of this content in a controlled and protected manner. Although the content providers may choose to sell a copy of a digital recording, there is strong resistance to having unauthorized copies distributed over computer networks, on optical discs, or in other formats.
Content protection systems and Digital Rights Management (DRM) technologies have been developed to combat pirating, but, in many cases, are cracked within weeks or months of their introduction. For example, digital direct broadcast satellite providers like DirecTV and BSkyB have fought a pitched battle against pirates who sell illegal Smart-Cards as well as entire set-top boxes that allow the reception of programming, including premium channels, without paying premium or subscription fees.
More recently, the DVD was introduced. The DVD standard incorporates the Content Scrambling System (CSS) for encryption of audio-visual content. After the commercial release of the DVD, the Content Scrambling System was broken and a software program (DeCSS) to defeat the system was made available on the Internet. The ability to freely copy DVDs is now available to anyone with a personal computer and DVD-ROM drive. Pirated copies of many DVD movies are readily available on the Internet and through the black-market or underground dealers.
B. Metadata
Unlike text-based computer data files, video and audio media are not inherently self-describing in a manner that is easily readable by computers. Self-description is a necessary aid in the classification, indexing, manipulation, filing and playing of data files. To ameliorate this situation, audio and video content is typically augmented with machine readable “metadata”. Metadata is generally defined, for the purpose of this patent, as any type of information added to a media file that helps identify or describe an attribute of the media content or is associated with the generation and/or production of the media content.
The metadata typically consists of several data fields, each data field being dedicated or reserved for a particular type of information. Thus, the metadata could include fields dedicated to some fundamental elements of the content such as title, artist, year of production, copyright holder and genre. Metadata fields may also be assigned to more detailed or complex parameters such as the cast and crew of a film, encryption method, equalization parameters, video scaling requirements, recommended decoding buffer size, how the content is best presented, or links to other information or other content.
A number of standards exist for metadata for both audio and video. For example, MPEG-1 Level-3 (MP3) audio files are often labeled (or “tagged”) using the de-facto standard called ID3. ID3 is a relatively simple text enhancement to compressed audio files that indicates titles, artists, album names, years, genres, and other descriptive parameters. MPEG-7 is a new international standard (ISO/IEC 15938) for metadata, allowing for a richly detailed description of audio-visual material.
Many other metadata systems (some of which have been standardized) exist. These systems all enable data associated with media content to be authored, stored, transported and associated with the content. The standards do not address how the metadata is managed or how to restore the metadata fields if the content becomes disassociated from the metadata, or how the metadata can be used as a means of controlling the playing of the media. More specifically, the standards do not address the use of metadata to determine whether the media is to be accepted as a bona fide media or rejected as an unauthorized copy.
The media content generally consists of audio and/or video components and is sometimes referred to as ‘the payload’. The combination of metadata and the payload is defined herein as a media file having a header, a main body and a trailer. The metadata can be placed in a particular position within the media file (for example, right after an introductory header, or before the trailer). The metadata can also be interspersed or interleaved with portions of the payload. Alternatively, the metadata can also be embedded within the payload.
A player receiving the media file (either as a block of data on a transportable data storage such as a magnetic or optical disc, or received over a network interface in a stream) detects the information from at least some of the fields of the metadata and may use this information to set some of its parameters to insure that the payload is played correctly.